Horton

Re: ALTER TABLE .. DETACH PARTITION CONCURRENTLY

Alvaro Herrera <alvherre@alvh.no-ip.org>

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From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: Amit Langote <amitlangote09@gmail.com>, pgsql-hackers@lists.postgresql.org
Date: 2021-03-17T17:48:43Z
Lists: pgsql-hackers

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On 2021-Mar-15, Alvaro Herrera wrote:

> Here's a fixup patch to do it that way.  I tried running the commands
> you showed and one of them immediately dies with the new error message;
> I can't cause the bogus constraint to show up anymore.

Actually, that was a silly fix that didn't actually work correctly, as I
discovered immediately after sending it.  The right fix is to forbid all
commands other than DETACH PARTITION FINALIZE in a partition that's in
the process of being detached.

In the attached v8, I did that; I also added a ton more tests that
hopefully show how the feature should work in concurrent cases,
including one case in which the transaction doing the detach is
cancelled.  I also renamed "inhdetached" to "inhdetachpending", per
previous discussion, including changing how to looks in psql.

I am not aware of any other loose end in this patch; I consider this
version final.  Barring further problem reports, I'll get this pushed
tomorrow morning.

psql completion is missing. If somebody would like to contribute that,
I'm grateful.

-- 
Álvaro Herrera                            39°49'30"S 73°17'W
"If you have nothing to say, maybe you need just the right tool to help you
not say it."                   (New York Times, about Microsoft PowerPoint)

Commits

  1. Make detach-partition-concurrently-4 less timing sensitive

  2. Improve documentation on DETACH PARTITION lock levels

  3. Track detached partitions more accurately in partdescs

  4. Allow a partdesc-omitting-partitions to be cached

  5. Fix relcache inconsistency hazard in partition detach

  6. Don't add a redundant constraint when detaching a partition

  7. ALTER TABLE ... DETACH PARTITION ... CONCURRENTLY

  8. Let ALTER TABLE Phase 2 routines manage the relation pointer

  9. Check default partitions constraints while descending